Internal riser inspection device

Abstract

An internal inspection unit for pipe has ultrasonic transducers that inspect weld volume, weld root, and wall thickness. The ultrasonic transducers are mounted to a portion of the inspection unit that is rotatable, but no more than one full revolution. One of the units has independently movable shoes for each separate transducer. The shoes are moved between retracted and extended positions by pneumatic cylinders. The other unit has shoes that support more than one transducer, the shoes being biased outwardly by springs.

Description

[0001]This application claims the provisional application filing date of Apr. 5, 2002, Ser. No. 60 / 370,444 entitled “Internal Riser Inspection Device.”FIELD OF THE INVENTION[0002]The invention relates in general to non-destructive testing of pipe, and in particular to a test unit that is conveyed internally through pipe for ultrasonically inspecting the pipe wall thickness and welds.BACKGROUND OF THE INVENTION[0003]Non-destructive testing of pipe has been done for many years utilizing ultrasonic transducers, eddy current measurements, x-ray and other techniques. Operators using pulse echo techniques with ultrasonic transducers can determine wall thickness, which is a measure of any corrosion that has occurred. For welds, operators have used flight diffraction (“TOFD”) techniques with ultrasonic transducers. Also, a method known as pulse echo shear wave has been combined with TOFD transducer measurements to inspect portions of the weld that are missed by the TOFD transducer.[0004]One...

AI Technical Summary

Benefits of technology

[0014]For the auxiliary lines, a smaller diameter unit is utilized. In this unit, multiple shoes are employed, but more than one transducer may be mounted to each shoe. The shoe is spring biased rather that urged by a pneumatic cylinder.

Problems solved by technology

The transport of the riser sections to a testing facility on land is expensive.

Also, it is time consuming to transport, clean, disassemble, inspect and reassemble the riser sections.

During this time, unless a spare drilling riser can be obtained, the drilling rig would not be able to operate.

Drilling rigs are very costly on a daily basis.

However, there are a number of problems in doing so.

The interior of the drilling riser is often not very clean, and may be coated with dried drilling mud.

Also, there is normally not much access room on the drilling rig at the ends of each riser section for staging the equipment necessary to do the inspection.

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